Glass mosaic ribbed bowl fragment late 1st century B.C.-early 1st century A.D. Roman Body fragment.Translucent cobalt blue and opaque white.Slightly convex curving side, tapering downward.Mosaic pattern formed from sections of a single cane in a blue ground with irregular white spiral threads; on exterior, two prominent vertical ribs, with flattened tops and rounded outer edges, tapering downwards, and above ribs, slight horizontal recess.Polished exterior; pitting and some weathering on exterior; dulling and iridescent weathering on interior and jagged edges.. Glass mosaic ribbed bowl fragment. Roman. late 1st century B.C.-early 1st century A.D.. Glass; cast and tooled. Early Imperial. Glass